# How to convert magnitudes to bolometric luminosity? [duplicate]

If we know a star's magnitudes from several bands(say u,g,r,i,z,J,H,k) and the star's distance, how to calculate Lbol?

Let's suppose the star has a black body spectrum. Is there any manual about the calculation? It's better to have a lot of technical details.

• Are you looking​ for something more complicated than find a bolometric correction? Apr 16 '17 at 8:07
• @Rob yes, these objects are cool and bright in infrared, but I know their magnitudes from 2MASS and WISE, and even Sloan. Convert magnitudes to flux and fit using a blackbody model is enough? Apr 16 '17 at 8:39
• They are certainly not blackbodies. You would need to fit with proper stellar models. Apr 17 '17 at 8:28
• @Rob If we know magnitudes and stellar type, how to calculate Lbol? Apr 17 '17 at 9:01
• I have added a reference to a relevant table for cool objects. Apr 20 '17 at 11:56

$M_{bol,*} - M_{bol,sun} = -2.5log_{10}(\frac{L_*}{L_{sun}})$
[leading to the accepted definition of] $M_{bol} = -2.5log_{10}(L_*) + 71.1974...$ , where the constant term is the zero-point luminosity $L_0$ .